The present invention relates to a single chamber dishwashing machine.
Conventionally, a single chamber dishwashing machine has a dish-cleaning compartment for washing and rinsing purposes. Soiled dishes are loaded onto a dish-rack, which is then transferred to the dish-cleaning compartment.
Initially, fresh water and detergent filling valves are activated to allow pre-determined amount of fresh water and detergent to flow into a water sump which is located within the dish-cleaning compartment. The mixture of fresh water and detergent (which is known as wash water or wash fluid) will then be heated up to a pre-defined temperature by a water heating system located at the water sump. Structurally, the water sump is built as part of the dish-cleaning compartment.
During a wash cycle, the loaded dish-rack is stationed at the dish-cleaning compartment and is sprayed with random pattern of wash water through two rotating spray arms which is located above and below the loaded dish-rack. The heated and chemically treated wash water is re-circulating through the rotating spray arms for a pre-determined period to remove all food residue and other contamination from the soiled dishes.
At the end of the wash cycle, a drain valve is activated to drain off all the xe2x80x9cusedxe2x80x9d wash water from the water sump. After the wash cycle, the dishwashing machine will proceed to a rinse cycle.
During the rinse cycle, fresh water and rinse agent filling valves is activated to allow a pre-determined amount of fresh water and rinse agent to inject into the water sump located within the dish-cleaning compartment. The mixture of fresh water and rinse agent (which is known as rinse water) will then be heated up to a pre-defined temperature by the water heating system located at the water sump.
The heated and chemically treated rinse water is sprayed randomly from the rotating spray arms onto the dishes to remove the left over of the wash water and to sanitize the dishes. Generally, the rinse water in conventional dishwashing machine is being cross-contaminated by the wash water. The reason being both wash water and rinse water are sharing the same rotating spray arms and are circulating through the same piping and pumping system.
Another major disadvantage of the conventional dishwashing machine is the wash water being heavily contaminated by the soiled dishes during the wash cycle due to a no effective pre-wash flush cycle being included. Besides, for every wash cycle, a completely fresh wash water make-up is needed. The intensive wash water make-up indirectly increases the overall consumption of fresh detergent per dish.
Yet another disadvantage of the conventional dishwashing machine is the ineffectiveness of the rotating spray arm cleaning method, which creates an inefficient random spraying pattern. Studies shown that a substantial area of the soiled dishes is not reachable by the random spraying pattern.
Another disadvantage of the conventional dishwashing machine is high temperature (about 180xc2x0 F.) of wash water and rinse water being used to heat up and to sanitize the dishes.
Lately, a number of dishwashing machine manufacturer tries to modify their dishwashing machine design by introducing a lower temperature and chemical sterilize washing method where more rinsing and sterilizing chemical is added into the rinse water. However, this method is still not very cost effective due to the extra chemical cost incurred.
Therefore, a few unique features are introduced in the present invention to address the disadvantages of the conventional dishwashing machine.
It is a primary object of the present invention to provide an improved and cost effective single chamber dishwashing machine.
Another object of the present invention is to provide a dishwashing machine having a dish-rack rotating mechanism to improve cleaning efficiency.
Yet another object of the present invention is to provide a dishwashing machine having multiple angles spraying pattern, where the dishwashing fluid is channeled from multiple locations, which includes top, bottom and side(s) of a loaded dish-rack.
A further object of the present invention is to provide a dishwashing machine having isolated re-circulating fluid spraying system and non re-circulating fluid spraying system to minimize cross contamination of the rinse fluid.
Another object of the present invention is to provide a pre-wash flush cycle to minimize cross contamination of the wash fluid.
According to the most general aspect of the invention, the object is accomplished by a single chamber dishwashing machine comprising:
a dish-cleaning compartment having a cover and a casing;
a re-circulating fluid spraying system wherein a re-circulating fluid is delivered to a re-circulating fluid spray arm;
a non re-circulating fluid spraying system wherein a non re-circulating fluid is delivered to a non re-circulating fluid spray arm;
a dish-rack rotating mechanism and drive for rotating a dish-rack holder a dish-rack;
a drainage mechanism for chanelling a used flush fluid a used wash fluid or a used rinse fluid from the dish-cleaning compartment to a designated drain location; and
a controlling means for controlling the dishwashing machine operation.
Preferably, the single chamber dishwashing machine further comprises:
a re-circulating fluid tank for holding the re-circulating fluid including a fresh wash fluid, the used wash fluid and the used rinse fluid;
a non re-circulating fluid tank for holding the non re-circulating fluid including a fresh flush fluid and a fresh rinse fluid;
a waste filter tank for filtering the used flush fluid, the used wash fluid and the used rinse fluid;
a re-circulating fluid pumping system for pumping the re-circulating fluid from the re-circulating fluid tank to the re-circulating fluid spray arm; and
a non re-circulating fluid pumping system for pumping the non re-circulating fluid from the non re-circulating fluid tank to the non re-circulating fluid spray arm.
Preferably, the dishwashing machine further comprises of an automated chemical dispenser for facilitating a cleaning detergent and other cleaning/rinsing chemical dispensing.
Also, preferably, the re-circulating fluid spray arm and the non re-circulating fluid spray arm are pivotable for swinging a water jet.
The above and other objects, features, aspects and advantages of the present invention will become clearer from the following detailed description of the present invention when taken in connection with the accompanying drawings.
The drawings are for purpose of illustration only and not intended as a definition of the limits of the invention. It being understood that various changes in the details may be made without departing from the spirit and advantages of the present invention.